mapOfSize

mapOfSize

Matcher for a Map with exactly the expected size.

Matchers are applied through assertObjectMatches, where they narrow the corresponding property type.

Type information that already exists in the calling scope is incorporated.

Usage

import { assertObjectMatches, mapOfSize } from "@kensio/smartass";

const value: unknown = {
  headers: new Map([["content-type", "application/json"]]),
};

assertObjectMatches(value, {
  headers: mapOfSize(1),
});

// value is now narrowed to an object with a Map of exactly 1 entry
// {
//   headers: Map<unknown, unknown> & { readonly size: 1 };
// }

Source

Source file: src/assert/map-size/map-size.match.ts